JPH11169998A - Forming punch device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability of a punch main body and a sleeve member by restraining the thermal expansion of the punch main body owing to the forming heat of a stock to which a pressurizing force is imparted under the cooling operation for the punch main body. SOLUTION: The device is provided with the punch main body 30 which imparts the pressurizing force on a secondary formed part 48 being a forging stock, guide sleeve 54 which is fit around the outer peripheral part of the punch main body 30, and a cooling means 53 which executes the cooling operation for the punch main body 30 and the guide sleeve 54 by circulating coolant along a communicating passage 57 arranged between the punch main body 30 and the guide sleeve 54.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forming punch device capable of plastically deforming a material provided in a cavity of a mold member into a desired shape by applying a pressing force to the material. .

[0002]

2. Description of the Related Art Conventionally, a forging material is inserted into a forging cavity formed in an upper die and a lower die joined to each other, and a pressing force is applied to the forging material via a punch. 2. Description of the Related Art A mold apparatus for forging a material for use into a predetermined shape is known.

[0003] The present applicant has proposed a mold cooling method for this type of mold apparatus, which can greatly enhance the cooling effect and also improve the mold life (mold life) (Japanese Patent Application Laid-open No. Sho. No. 61-255737).

That is, as shown in FIGS. 12A and 12B, a predetermined amount of lubricant flows into the cavity 1 from above, and the lubricant flows through the outflow groove 3 formed in the knockout pin 2 into the cavity 1. After discharging from inside,
A method is employed in which a mold composed of an upper die 5 and a lower die 6 is cooled by blowing air into the cavity 1 through a passage 4 communicating with the outflow groove 3.

[0005] Reference numeral 7 denotes a billet after molding to which a pressing force is applied by a punch 8.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in connection with the above proposal, and has shown a thermal expansion of a punch body due to molding heat of a material to which a pressing force is applied while cooling the punch body. It is an object of the present invention to provide a molded punch device capable of improving the durability of the punch body and the sleeve member by suppressing the above.

[0007]

In order to achieve the above-mentioned object, the present invention provides a punch body for applying a pressing force to a material disposed in a cavity of a mold member, and an outer peripheral portion of the punch body. And a sleeve member which is mounted so as to surround a part of the punch body and is displaced integrally with the punch body, and is provided between the punch body and the sleeve member, and performs a cooling action on the punch body and the sleeve member. Cooling means;
It is characterized by having.

In this case, the cooling means has a communication passage formed between the punch body and the sleeve member, and the cooling means is operated by a cooling medium flowing along the communication passage. Can be suitably cooled.

The cooling means has a cylindrical intermediate member interposed between the punch body and the sleeve member, and is provided between the sleeve member and the intermediate member and between the punch body and the intermediate member. The punch body and the sleeve member can be suitably cooled under the action of a cooling medium flowing along the first communication path and the second communication path formed respectively in the punch body.

Further, the outer diameter of the sleeve member is
The sleeve member is set to be larger than the inner diameter of the hole of the ring body provided in the mold member, and the sleeve member is pressed into the hole of the ring body when the punch body applies a pressing force to the material. Thereby, the coaxiality of the obtained molded product can be maintained with high accuracy.

Further, by forming a plurality of holes in the outer peripheral portion of the sleeve member and providing graphite in the plurality of holes, good lubrication characteristics can be obtained and generation of galling can be suppressed. In this case, the sleeve member and the ring body are each formed of a different metal material,
Moreover, it is preferable that the ring body be formed of a metal material harder than the sleeve member.

[0012] By attaching the sleeve member to the punch body detachably, it can be easily replaced with another new sleeve member.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a forming punch device according to the present invention will be described below in detail with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 denotes a forging die into which a forming punch device 11 according to the present embodiment is incorporated.

The forging die 10 is provided with a first die holder 14 having a plurality of guide means 12a to 12d erected near four corners, and laminated at the center of the first die holder 14. And a second die holder 16 and a third die holder 18.

A thick press-fit ring 20 formed integrally is fixed on the second die holder 16 via fastening means 22, and a thin-walled sleeve is formed in a hole of the press-fit ring 20. The upper dice 26 and the lower dice 28 are integrally joined via 24. The fastening means 2
2 is a fixing plate 2 that engages with the step of the press-fit ring 20.
7 and a plurality of bolts 29 for holding the fixing plate 27 to the first die holder 14.

On the upper surface of the upper die 26, there is formed a first hole 32 into which a punch body 30 described later is press-fitted.
A ring body 34 is integrally joined, and a second ring body 36 fitted to the first ring body 34 is integrally joined to the upper surface of the sleeve 24. In this case, the first ring body 34 and the second ring body 36 may be integrally formed as one ring body without being configured separately.

Incidentally, one end of the punch body 30 which is pressed into the hole 32 of the first ring body 34 has a desired uneven shape corresponding to the uneven shape of the product to be forged.

The first ring body 34 is made of, for example, a super hard material and subjected to shrink fitting.
6 is strongly tightened toward the center. Further, the first ring body 34 and the second ring body 3
The upper die 6, the lower die 28, and the sleeve 24 are integrally joined by being tightened by a tapered portion of a fastening ring 40 screwed into a screw hole of the press-fit ring 20.

In this case, a cavity 42 is formed by the first ring body 34, the upper die 26 and the lower die 28, and a knockout pin 44 for extruding a forged product is provided below the cavity 42 on the second die holder 1.
6 and the third die holder 18 are disposed so as to be able to advance and retreat along a hole 46 formed in the third die holder 18. In this cavity 42,
A secondary molded product 48 as shown in FIG. 8D is loaded as a forging material.

Above a predetermined distance from the press-fit ring 20, a ram (not shown) of a mechanical press (not shown) is connected, and is displaced vertically with the ram under the driving action of the mechanical press. An elevating member 50 is provided.

A holder 5 is provided on the bottom of the elevating member 50.
2, a forming punch device 11 is fixedly mounted, and the forming punch device 11 is moved up and down by a plurality of guide means 12 a to 12 d erected on the first die holder 14.
It is provided so as to be displaceable along the vertical direction integrally with the zero.

As shown in FIG. 3, the forming punch device 11 includes a punch body 30 fixed to a bottom portion of a lifting member 50 via a holder 52, and cooling means for cooling the punch body 30 to a predetermined temperature. 53 and the punch body 30
And a guide sleeve (sleeve member) 54 formed of a cylindrical metal material.

The guide sleeve 54 is detachably held via a lock ring 55 which engages with a step portion of the guide sleeve 54 and is screwed into a screw portion of the punch body 30. As shown in FIG. 5, graphite holes are formed in the outer peripheral surface of the guide sleeve 54.
6 is buried, so that the hole 32 of the first ring body 34 is formed.
The lubricating characteristics when press-fitted into the substrate can be kept good. In this case, the outer diameter of the guide sleeve 54 fitted to the punch body 30 is set slightly larger than the inner diameter of the hole 32 of the first ring body 34.

The guide sleeve 54 is made of, for example, S
It is preferable that the first ring body 34 be formed of a material harder than the guide sleeve 54, such as a metal material such as KD11, FC25, or FC30.

The cooling means 53 is formed between the guide sleeve 54 and the punch main body 30 and has a communication passage 57 through which a cooling medium flows. The communication passage 57 is provided with a cooling medium supply passage formed in the punch main body 30. It is formed so as to communicate with the port 58a and the cooling medium discharge port 58b. As the cooling medium, a cooling liquid, water, air, gas or the like is used.

As shown in FIG. 1, the cooling medium supply port 58a and the cooling medium discharge port 58b are connected to pipe joints 60a and 60b provided on the holder 52, respectively, and are connected to the pipe joints 60a and 60b. A cooling medium is supplied from a cooling medium supply source (not shown) via a tube (not shown).

The communication passage 57 is formed between the guide sleeve 54 and the punch main body 30 as shown in FIGS. 3 and 4, communicates with the cooling medium supply port 58a, and extends along the axial direction of the punch main body 30. A first passage 62a descending;
A second passage 62b that is bent from the first passage 62a and circulates along the outer peripheral portion of the punch body 30;
a third passage 62c bent upward from b and circling substantially parallel to the second passage 62b; and a fourth passage bent upward from the third passage 62c and circulating substantially parallel to the third passage 62c. A passage 62d, a fifth passage 62e bent upward from the fourth passage 62d and rotating substantially parallel to the fourth passage 62d, and a fifth passage 62e bent upward from the fifth passage 62e And a seventh passage 62g that is bent upward from the sixth passage 62f and communicates with the cooling medium discharge port 58b.

In this case, the first to seventh passages 62a
The first through seventh passages 62a through 62g are substantially formed of grooves having an arc-shaped cross section formed on the outer peripheral surface of the punch body 30, and are formed so that the first through seventh passages 62a through 62g communicate with each other.
Reference numerals 64a and 64b indicate a seal ring that keeps the communication passage 57 airtight or liquid-tight, and reference numeral 66 indicates a blind plug that closes one end of the first passage 62a and the seventh passage 62g. .

The forging die 10 incorporating the forming punch device 11 according to the embodiment of the present invention is basically constructed as described above. Next, the operation and effect of the forging die 10 will be described. I do. The following describes an example in which an outer cup forming a constant velocity joint is forged as a forged product.

By performing first forging on a cylindrical billet 68 as shown in FIG. 8A by a mold device (not shown), the diameter of the billet 68 is increased through a middle step as shown in FIG. 8B. Different primary molded articles 70 are obtained. Subsequently, after performing the preliminary molding on the primary molded article 70 (see FIG. 8C), the secondary forging is performed by another mold apparatus (not shown), as shown in FIG. 8D. A secondary molded product 48 having such a cup portion 72 and a shaft portion 74 is obtained.

The forging die 10 in which the forming punch device 11 according to the present embodiment is incorporated is a secondary molded product 48.
Is subjected to tertiary forging.

First, as a preparatory operation, the cavity 42 formed by the upper die 26 and the lower die 28
In the hole 32 of the first ring body 34 coaxially processed,
By fixing the punch main body 30 in a state where the punch main body 30 with the guide sleeve 54 fitted therein is inserted, the punch main body 30 is positioned with high concentricity with respect to the cavity 42.

In this case, a cooling medium supply source (not shown) is energized in advance, and a communication passage 5 formed between the guide sleeve 54 and the punch body 30 via a tube (not shown).
7 is supplied with a cooling medium.

In a state where the punch main body 30 is arranged at a raised position (not shown), the cavity 42 is charged with a secondary molded product 48 as a forging material. Then, the punch body 30 descends integrally with the lifting member 50 connected to the ram (not shown) under the driving action of a mechanical press (not shown), and forging is started when the state shown in FIG. 1 is reached. .

When the punch body 30 descends integrally with the elevating member 50, a plurality (for example, four) of guide means 12a to 12d provided between the elevating member 50 and the first die holder 14. The lateral eccentric load is suitably absorbed, and the punch body 30 is smoothly pressed into the center of the first ring body 34 via the guide sleeve 54.

At the start of forging, the guide sleeve 54 fitted on a part of the outer peripheral surface of the punch body 30
The punch body 30 and the guide sleeve 54 enter under the guide action of an annular groove (not shown) formed at the upper end of the hole 32 of the ring body 34, and further, the punch body 30 and the guide sleeve 54 are connected to the first ring. It is displaced integrally while being pressed into the hole 32 of the body 34.

In this way, the punch body 30 descends,
By reaching the molding end position shown in FIG. 2 from the molding start position shown in FIG. 1, the secondary body 48 which is a forging material is formed through the punch body 30, the lower die 28 and the upper die 26. On the other hand, forging is performed, and the forging material plastically flows along the shape of the cavity 42.

In this case, the first through seventh passages 62a-62 formed between the guide sleeve 54 and the punch body 30.
The punch body 30 is directly cooled by the flow of the cooling medium along the 62 g, and the frictional heat generated when the forging material is formed by the cooling action on the punch body 30 can be appropriately absorbed. Become. Therefore, the punch body 30 is prevented from being thermally expanded by the frictional heat, and the durability of the punch body 30 can be further improved.

It should be noted that the first ring 3
The frictional heat generated on the press-fitting surface of the guide sleeve 54, which is press-fitted into the hole 32 of the fourth, is also appropriately absorbed, so that the durability of the guide sleeve 54 can be improved.

After the forging is completed in this way, the punch body 30 is raised to a predetermined position integrally with the lifting member 50 connected to the ram (not shown) under the driving action of a mechanical press (not shown). As a result, the punch body 30 and the guide sleeve 54 are separated from the hole 32 of the first ring body 34, and are in a standby state for the next step. Then, the forged product 76 (see FIG. 9) is taken out under the displacement action of the knockout pin 44.

Here, the punch body 30 and the guide sleeve 54 provided with the cooling means 53 and the punch body 77 according to the comparative example not provided with the cooling means 53 are formed by forging and forming heat. FIG. 6 shows the temperature distribution. In addition, as a cooling medium in the cooling means 53, water at normal temperature was used. The molding heat does not include frictional heat.

As will be understood from FIG. 6, the cooling means 53
Punch body 30 and guide sleeve 54 provided with
It has been found that there are many parts where the temperature is low as compared with the punch body 77 without the cooling means 53.

For example, in the punch body 30 and the guide sleeve 54 provided with the cooling means 53, the portion provided with the first to seventh passages 62a to 62g through which the cooling medium flows is cooled to about 20 degrees or less. On the other hand, the temperature of the punch body 77 corresponding to the above portion is relatively high at 120 degrees or less.

FIG. 7 shows the relationship between the temperature of the guide sleeve 54 and the number of molding shots. In FIG. 7, characteristic curves L and M show the case where the guide sleeve 54 without the cooling means 53 is used, respectively, and the characteristic curve N
Shows the case where the guide sleeve 54 provided with the cooling means 53 is used.

The guide sleeve 5 according to the characteristic curve L
In No. 4, the press fitting allowance for the first ring body 34 is about 0.03.
mm, in the guide sleeve 54 according to the characteristic curve M, the press-in allowance was set to about 0.01 mm, and in the guide sleeve 54 according to the characteristic curve N, the press-in allowance was set to about 0.01 mm.

Guide sleeve 54 provided with cooling means 53
Since the rise in temperature was suppressed even when the number of molding shots was increased and the temperature was kept substantially constant at a low temperature (about 20 degrees), no baking occurred on the first ring body 34. On the other hand, in the guide sleeves 54 related to the characteristic curves L and M without the cooling means 53, the number of molding shots increased and the temperature rose, and the guide sleeves 54 were burned.

As described above, in the present embodiment, the frictional heat between the forging material and the punch body 30 is suitably absorbed through the cooling means 53, so that the thermal expansion is suppressed and the punch body 30 is removed. The durability can be further improved.

Since the cooling means 53 is constituted by a simple mechanism, it can cope with mass production.

Further, in this embodiment, while the punch body 30 is pressed into the hole 32 of the first ring body 34 via the guide sleeve 54, a pressing force is applied to the forging material, and Since the main body 30 is not misaligned in the lateral direction, as shown in FIG.
Thus, the coaxial accuracy between the axis E of the cup portion 78 of the outer cup and the axis F of the shaft portion 79 can be maintained with high accuracy.

Furthermore, the guide sleeve 54 and the first ring body 34 are each formed of a different metal material, and the graphite 56 buried in the guide sleeve 54 maintains the lubrication characteristics well, so that the guide The occurrence of galling on the sliding surfaces of the sleeve 54 and the first ring body 34 can be suppressed.

Furthermore, by providing the guide sleeve 54 detachably with respect to the punch body 30 via the lock ring 55, the guide sleeve 54 can be easily replaced with another new guide sleeve 54. There are advantages.

In the present embodiment, the outer cup constituting the constant velocity joint is used as a forging material, but the invention is not limited to this. For example, a stepped part (not shown), a stepped gear, etc. It is needless to say that the present invention can be applied to various forged products requiring coaxial accuracy between a part of a part and another part.

Next, a forming punch device 80 according to another embodiment of the present invention is shown in FIGS. The same components as those of the forming punch device 11 shown in FIG. 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.

The forming punch device 80 according to the present embodiment.
Has a substantially cylindrical intermediate member 86 interposed between the guide sleeve 82 and the punch body 84, and between the guide sleeve 82 and the intermediate member 86, and between the punch body 84 and the intermediate member 86.
Between the first communication passage 88 and the second communication passage 90
Is different from the forming punch device 11 according to the embodiment.

That is, a cooling medium supply port 58a and a cooling medium discharge port 58b are formed on the upper side of the intermediate member 86 so as to face each other.
A first communication passage 88 is formed so as to spiral around the guide sleeve 82 and the intermediate member 86, and a second communication passage 90 communicating with the cooling medium discharge port 58b is formed in the punch body 84. The intermediate member 86 is formed so as to spiral around.

In this case, as shown in FIG. 11, the first communication passage 88 and the second communication passage 90 are substantially arc-shaped in cross section formed on the outer peripheral surface and the inner peripheral surface of the intermediate member 86, respectively. The first communication passage 88 and the second communication passage 90 are formed so as to communicate with each other via a space 92 (see FIG. 10) closed on the lower end side of the intermediate member 86.

The other configuration, operation, and effect of this embodiment are the same as those of the above-described embodiment, and therefore, detailed description thereof will be omitted.

[0059]

According to the present invention, the following effects can be obtained.

That is, by cooling the punch body and the sleeve member through the cooling means, the frictional heat between the material to which the pressing force is applied and the punch body is suppressed, and the durability of the punch body is improved. Can be.

Further, since the punch body does not cause misalignment in the lateral direction, it is possible to maintain the coaxiality of the obtained forged product with high accuracy.

Further, it is possible to suppress the occurrence of galling on the sliding surface of the sleeve member.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a forging die into which a forming punch device according to an embodiment of the present invention is incorporated.

FIG. 2 is an operation explanatory view showing a state where the punch body has been lowered from the forging start position shown in FIG. 1 and forging has been completed.

FIG. 3 is a longitudinal sectional view of the forming punch device shown in FIG.

FIG. 4 is a plan view of an outer peripheral surface of the punch main body for describing a passage formed in the punch main body.

FIG. 5 is a perspective view of a guide sleeve externally fitted to the punch body.

FIG. 6 is an explanatory diagram showing a temperature distribution of the punch body shown in FIG. 3 and a punch body according to a comparative example.

FIG. 7 is an explanatory diagram showing the relationship between the number of shots of the guide sleeve and the temperature.

FIGS. 8A to 8D are explanatory views showing a manufacturing process of an outer cup constituting a constant velocity joint.

9 is a longitudinal sectional view of a forged product forged by the forging die shown in FIG.

FIG. 10 is a longitudinal sectional view of a forming punch device according to another embodiment of the present invention.

FIG. 11 is an explanatory diagram of a communication path formed in an intermediate member included in the forming punch device shown in FIG.

FIG. 12A is a longitudinal sectional view of a forging die device according to the related art devised by the present applicant, and FIG. 12B is a sectional view taken along line BB.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Forging die 11, 80 ... Molding punch apparatus 12a-12d ... Guide means 14, 16, 1
8 die holder 20 press-fit ring 26, 28 die 30, 84 punch body 32, 46 hole 34, 36 ring body 42 cavity 44 knockout pin 50 lifting member 52 holder 53 cooling means 54 82 Guide sleeve 55 Lock ring 57, 88, 90 Communication path 58a Coolant supply port 58b Coolant discharge port 60a, 60b
... pipe joints 62a-62g ... passages 86 ... intermediate members

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B21J 3/00 B21J 3/00 5/02 5/02 A // B21K 1/14 B21K 1/14 A

Claims (8)

[Claims] 1. A punch body for applying a pressing force to a material disposed in a cavity of a mold member, and mounted so as to surround a part of an outer peripheral portion of the punch body, and integrated with the punch body. And a cooling means provided between the punch body and the sleeve member for performing a cooling action on the punch body and the sleeve member. 2. The apparatus according to claim 1, wherein the cooling means has a communication passage formed between the punch body and the sleeve member, and under the action of a cooling medium flowing along the communication passage. A molding punch device wherein the punch body and the sleeve member are cooled. 3. The apparatus according to claim 1, wherein the cooling means has a tubular intermediate member interposed between the punch body and the sleeve member, and between the sleeve member and the intermediate member and the punch. The punch body and the sleeve member are cooled under the action of a cooling medium flowing along a first communication path and a second communication path formed between the main body and the intermediate member, respectively. apparatus. 4. The apparatus according to claim 1, wherein the outer diameter of the sleeve member is set to be larger than the inner diameter of the hole of the ring member provided in the mold member, and the punch body is made of a material. The forming punch device wherein the sleeve member is press-fitted into a hole of the ring body when a pressing force is applied thereto. 5. An apparatus according to claim 1, wherein a plurality of holes are formed in an outer peripheral portion of the sleeve member, and graphite is provided in the plurality of holes. 6. An apparatus according to claim 4, wherein said sleeve member and said ring body are formed of different kinds of metal materials. 7. An apparatus according to claim 6, wherein the ring body is formed of a metal material harder than the sleeve member. 8. The apparatus according to claim 1, wherein the sleeve member is detachably attached to the punch body.